Tendon approximator

ABSTRACT

A tendon approximator employs two connected, normally closed clamps, which are each formed from two extruded elements. The two extruded elements are connected together in their mid-region by means of non-circular cam on a base element and a corresponding non-circular cam surface on a clamping element. In the normally closed position of the individual clamps, the cam and cam surface urge the device into a jaw-closed position with the handles being spaced apart. In a preferred embodiment two of the clamps are connected by means of rods extending through corresponding handle portions of the two clamps.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a division of our earlier filed U.S. patentapplication Ser. No. 263,518, filed Oct. 27, 1988, now U.S. Pat. No.4,957,500.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention concerns a normally closed clamp and moreparticularly a normally closed disposable surgical clamp particularlyadapted to pinch a blood vessel (artery or vein) and to prevent flow ofblood through the blood vessel during surgical procedures. The clamp maybe effectively used as a separator as its jaws open from the normallyclosed position. Two of the clamps may be joined in a useful tendonapproximator for use in tendon ligating procedures.

2. Description of the Prior Art

There are numerous available normally closed clamps which are employedin surgical procedures. Many of the clamps are made of stainless steelor other sterilizable materials which, because of their expense, must berecovered, autoclaved or otherwise sterilized, and reused. Many of thesurgical clamps generate excessive closing pressures in their normallyclosed position and as a result may cause damage to the delicate wallsof pinched blood vessels. Some of the available surgical clamps requirespecial tools for opening the jaws of the clamp to receive a bloodvessel. Some clamps require a special tool to re-open and remove theclamps when the surgical procedure is completed.

There is a need for a lightweight, inexpensive, sterile clamp which canbe employed as a surgical clamp, easily opened when desired, providingadequate but not excess closing jaw pressure, easily removed without theneed of additional tools and sufficiently inexpensive to justify singleuse without requiring recovery and re-sterilization.

STATEMENT OF THE PRESENT INVENTION

According to the present invention, a two-piece clamp is provided.Preferably each part is extruded linearly or molded from lightweight,flexible, plastic substances. The linear extrusions are slicedtransversely to produce a clamp base member and a clamp clamping memberwhich are slide-fitted together to form a normally closed clamp havingnormally closed jaws at one end and normally spaced-apart handle membersat the other end. In the central region of the normally closed clamp, acam member is provided on the base member and a cam-engaging surface isprovided on the clamping member. The cam member and the cam-engagingsurface are engaged at least in part. The surface of the cam member is anon-circular, arcuate surface. The cam-engaging surface applies a torqueurging the jaw members into proximity and provides a greater torque whenthe jaw members are spaced-apart as a result of drawing together thehandle members.

The clamp can be used by an operating surgeon or his operatoryassistants. The normally closed clamp is opened by squeezing the handlemembers together. The normally closed clamp returns to its normallyclosed position when the handle members separate. The two components arepreferably fabricated from inexpensive, lightweight, plastic substancessuch as polyethylene, polypropylene, polyurethane, polyesters,polyamides, polycarbonates and other substances which are limitedlyflexible. The clamp base member does not require the limited flexibilityand may be fabricated from other materials such as rigid plastics,metals, e.g., extruded aluminum alloy.

The normally closed clamp can also be employed as a separator device ora spreading device. The jaw members of the normally closed device can beplaced between two tissues and the handle members can be broughttogether whereby the jaw members spread apart to separate the tissues.In this use, the jaw members are preferably tapered and provided withblunt tips to avoid tissue damage. The advantage of the present normallyclosed spreading device as a tissue separator is that the operator canspread the jaw members conveniently by squeezing the handle members.Moreover the extent of movement of the jaw members is predictable;excessive spreading cannot occur which might result in damage to theseparated tissues. This should be contrasted with the present tissuespreaders which function in the manner of scissors--the surgeon spreadsapart the handle members causing a corresponding spreading of thespreader jaw members. Such spreading devices can be opened excessivelycausing tissue damage.

The normally closed device also may be employed as a membrane separator,particularly in delicate surgical procedures such as the Jannetaprocedure in which the surgeon separates a nerve from a blood vessel.The Janneta procedure employs a surgical cutting to separate a bloodvessel from an engaged nerve. Because of the size of the blood vesselsand nerves, the surgery is delicate and has many pitfalls. The presentdevice permits gentle separation of a nerve from an adjoining bloodvessel. The relative movement of the jaws is undirectional--that is, onejaw (the base element jaw) remains stationary while the other jaw moveslaterally and can slide between the contacting nerve and blood vessel.In this manner the nerve is separated from the blood vessel withoutrequiring surgery. For this separating use, the device should havetapering, blunt-tipped jaw members.

A still further use of the present clamp members is in tendonapproximation. Tendon approximators are employed to retain abuttingtendon ends in confrontation to permit surgical ligation of the tendon.The present clamp members may be provided with one or more boresextending transversely through one or both of the elements. A rigid wireor rod, preferably stainless steel, is press-fitted into the bore ofeach of two clamps. Each clamp retains one end of a tendon. The twoclamps may be advanced toward each other by sliding along the one ormore wires or rods until the tendon ends are in confrontation. Theclamps will retain that configuration until the tendon ligation iscompleted.

A still further alternative to the present invention is to provide anextruded arcuate finger on one or the other of the clamp members suchthat the arcuate finger, extending from one handle member, is engagedwith the inner surface of the other handle member. When the handlemembers are drawn together, the arcuate finger is further distorted andapplies an increasing torque tending to return the clamp to theirnormally closed position. When the handle members are released, thearcuate finger applies a torque tending to restore the normally closedcondition. The arcuate finger may be employed in addition to thenon-circular cam surfaces previously described to maintain the normallyclosed configuration. Alternatively the cam surfaces may be circular andall of the restoring torque may be provide from the arcuate finger.

A further embodiment of the invention is adapted for use as a towelclamp. At the present time, surgical steel towel clamps are employed toconnect toweling which drapes those regions of a surgical patient'sanatomy which are not exposed during the particular surgical procedure.Multiple clamps are used to secure the disposable fabric. The existingtowel clamps are normally surgical steel instruments which arerecovered, autoclaved and reused. In this embodiment of the invention,the jaw members have concave confronting surfaces and terminate in a tipwhich preferably sharpened or pointed. In the normally closed position,the jaw members are urged into tip-to-tip engagement and the concave jawsurfaces provide an opening for receiving fabric edges. In thisembodiment, the normally closed clamps can be discarded along with thetowels.

In a still further embodiment, a normally closed clamp is provided withjaw liners formed from soft pliable material such as plastic, rubber orpreferably foamed polymeric substances. The inserts may be secured to aconfronting jaw surface by means of adhesives or other fasteningtechniques. By employing dual durometer extrusion procedures, the softpliable jaw liner can be extruded directly into the clamp element.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of the two piece, normally closed clamp inits normally closed position.

FIG. 2 is a side elevation of the normally closed clamp in its openposition.

FIG. 3 is a perspective illustration of the clamp of FIGS. 1 and 2having a vessel secured between the jaws.

FIG. 4 is a side elevation of the normally closed clamp showing a vesselpinched between the jaws.

FIGS. 5 and 6 are fragmentary illustrations of extrusion blanks forproducing the normally closed clamp.

FIG. 7 is a fragmentary illustration of a base jaw member showing atransverse channel.

FIG. 8 is a side elevation of confronting jaw members with confrontingchannels.

FIG. 9 is a side elevation of confronting jaw members havingcorresponding grooves and beads.

FIG. 10 is a side elevation of confronting jaw members having serrationson the confronting jaw faces.

FIGS. 11 and 12 are side elevations of an alternative construction ofthe present normally closed clamp in the normally closed position (FIG.11) and in the open position (FIG. 12).

FIG. 13 is a side elevation of a normally closed clamp having tapered,blunt-tipped jaw members for use as a tissue spreader.

FIG. 14 is a sketch showing the use of the normally closed spreaderdevice for separating a vein from an engaging blood vessel.

FIG. 15 is a side elevation of an alternative embodiment of the normallyclosed clamp in the normally closed position.

FIG. 16 is a side elevation of the embodiment of FIG. 15 in the openposition.

FIG. 17 is a side elevation of a further embodiment of the normallyclosed clamp in its normally closed position.

FIG. 18 is a side elevation of the embodiment of FIG. 17 in its openposition.

FIG. 19 is a side elevation of the normally closed clamp illustratingbores in the base element.

FIG. 20 is a plan view of two normally closed clamps of the type shownin FIG. 19 connected together to function as a tendon approximator.

FIG. 21 is a fragmentary side elevation of modified jaw elements of FIG.8 engaged in their normally closed position with a secured tendon.

FIGS. 22 and 23 are side elevation views of a further alternativeconstruction of the present normally closed clamp in the normally closedposition (FIG. 22) and in an open position (FIG. 23).

FIGS. 24 and 25 are side elevation view of a still further embodiment ofthe present normally closed clamp in the normally closed position (FIG.24) and in an open position (FIG. 25).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a side elevation of the present, normally closed clamp 10having a base member 11 and a clamping member 12. The base member 11includes a jaw member 13, a handle member 14 and a central,non-circular, cam element 15. The clamping member 12 includes a jawmember 16, a handle member 17, a central body member 18 including acam-engaging surface 19 which is engaged at least in part with thesurface of the central, non-circular, cam element 15.

It will be observed in FIG. 1 that the normally closed clamp 10 has itsjaw members 13, 16 in a normally closed relation and its handle members14, 17 in a normally spaced-apart relation. The cam-engaging surface 19corresponds to the surface of the cam element 15 and the plasticmaterial forming the clamping member 12 has a minimum flexure urging thejaw members 13, 16 into proximity.

In FIG. 2, the handle members 14, 17 are drawn together and the jawmembers 13, 16 are spaced-apart. Confronting surfaces 21, 22 arepresented angularly to one another. It will be further observed fromFIG. 2 that the cam-engaging surface 19 has been distorted from itsnormal shape and the surface 19a has advanced upwardly along the surface20 of the cam element 15, causing a change in shape of the cam-engagingsurface 19 which creates increased flexural stress tending to urge thecam-engaging surface 19 back into its normal position relative to thecam element 15. When the handle members 14, 17 are released, theflexural stress in the cam-engaging surface 19 causes the clamp 10 toreturn to its normally closed position and, as shown in FIG. 3 and FIG.4, to pinch a vessel 23 which is positioned between the jaw members 13,16.

As shown in FIG. 4, beads 24 may be provided in the outer surfaces ofthe handle members 14, 17 to facilitate gripping the clamp handle member14, 17.

The base member 11 may be fabricated from non-flexible materials such asaluminum alloy, stainless steel or rigid plastics. The clamping member12 is formed from a limitedly flexible plastic such as polyethylene,polypropylene, polyurethane, polyesters, polyamides, polycarbonates andother materials which have sufficient rigidity to retain their shapewhen the clamp is opened--that is, the jaw member 16 and handle member17 move together, yet the cam-engaging surface 19 distorts over theouter surface 20 of the cam member 15 as the clamp is opened and closed.

Preferably the clamping member 12 and base member 11 are formed fromlinear extrusions of the selected thermoplastic material as shown inFIGS. 5 and 6. FIG. 5 illustrates the extrusion 11' for the base member11. FIG. 6 illustrates the extrusion 12' for the clamping member 12.Each of the extrusions 11', 12' is sliced into transverse sectionshaving a thickness of about 1 to 15 millimeters.

Additional features of the clamps may include a transverse channel 25 inthe base jaw member 13 as shown in FIG. 7. The channel 25 will securethe location of a vessel between the clamp jaws.

As shown in FIG. 8, a channel 26 may be provided in each of the jawmembers 13, 16 to secure the location of a retained vessel.

In order to provide improved gripping between the jaw members, aplurality of grooves 27 and a plurality of corresponding beads 28 may beextruded in the clamping jaw member 16 and the base jaw member 13respectively as shown in FIG. 9.

FIG. 10 illustrates serrations which are extruded in the confrontingsurfaces 21, 22 of the clamping jaw member 16 and base jaw member 13respectively to improve gripping action of the clamp.

An alternative embodiment of the present invention is illustrated inFIGS. 11, 12 wherein the clamp 40 is shown in a normally closed positionin FIG. 11 and in an open position in FIG. 12. The clamp 40 has a basemember 41 and a clamping member 42. The base member 41 includes a basejaw member 43, a base handle member 44 and a base cam member 45. Theclamping member 42 has a clamping jaw member 46, a clamping handlemember 47 and a central body member 48 which includes a cam surface 49.In the normally closed position of FIG. 11, the jaw members 43, 46 arein proximity and the handle members 44, 47 are spaced-apart. In thiscondition, the cam member 45 and cam surface 49 exert a minimum torquetending to urge the jaw members 43, 46 into proximity. When the handlemembers 44, 47 are brought together as shown in FIG. 12, the cam surface49 slides over the cam member 45 and the jaw members 43, 46 arespread-apart. The torque applied by the cam members 45 and cam surface49 in the clamp-open position of FIG. 12 is greater than the torqueexisting in the normally closed clamp position of FIG. 11. It will beobserved that the cam member 45 has a non-circular, arcuate shape andthat the cam surface 49 has a corresponding non-circular, arcuate shape.The flexure of the cam surface 49 causes the clamp 40 to seek thenormally closed position shown in FIG. 11.

Use As A Separator

The normally closed clamp of this invention also may be employed as aseparator for separating tissues. The jaw members of the clamp aretapered and provided with blunt tips as shown in FIG. 13. The separatordevice 50 (also a normally closed clamp) has a base element 51 and apivotal element 52. The base element 51 has a tapered jaw member 53, ahandle member 54 and a central cam member 55. The pivotal member 52includes a tapered jaw member 56, a handle member 57 and a central bodyportion 58 including a cam engaging surface 59. Each of the tapered jawmembers 53, 56 is provided with a blunt tip 60, 61 respectively.

The separator device 50 can be employed in surgical procedures where itis desirable to spread apart body tissues or tendons, blood vessels,nerves, et cetera. When the handle members 51, 57 of the separatordevice 50 are drawn together, the jaw members 53, 56 spread apart to aknown width. This is particularly important. The state-of-the-artspreader devices employ a scissors principle which requires theoperating surgeon to spread the scissors handle elements in order tospread the scissors jaw elements. Normally there is no stop mechanism onthe existing separator devices. Excessive spreading may cause tissuedamage.

A specialized use of the separator device of FIG. 13 is illustrated inFIG. 14. A surgical procedure known as the Janneta procedure is employedto separate a nerve which may be positioned in contact with a smallblood vessel. Customarily in the Janneta procedure, a nerve is cut awayfrom the engaging blood vessel by means of a sharp knife. Such cuttingrequires care and delicacy and presents opportunities for error. Asillustrated in FIG. 14, a blood vessel 62 is shown in contact with anerve 63. The nerve 63 and blood vessel 62 are separated at the spaces64a, 64b. The tapered jaw members 53', 56' of the spreader device 50'are introduced (as indicated by the broken line) into the space 64abetween the nerve 63 from the blood vessel 62. The operating surgeonsqueezes the handle members 51', 52' until the clamping jaw 56' moves tothe right while the base jaw 53' remains in the space 64a. Thus thetapered jaw member 56' slides between the nerve 63 and blood vessel 62urging a separation. The separator device 50' is moved along the lengthof the blood vessel 62 until the engagement with the nerve 63 isentirely opened at the space 64b. Thereafter, in the Janneta procedure,a permanent spacer is positioned between the blood vessel 62 and thenerve 63 to prevent recurrence of the contact.

Alternative Construction

As shown in FIGS. 15-18, the resiliency needed to maintain the clamp ina normally closed position may be provided from an arcuate finger ofresilient plastic material which functions as a spring element. In FIG.15, 16, the clamp 10' has an arcuate finger 65 extending from the innerface of the base handle member 14' to the inner surface of the clampinghandle 17'. In the normally closed condition of FIG. 15, the arcuatefinger 65 is distorted and applies a torque urging the handle members14', 17' open and consequently urging the jaw members 15', 13' intoproximity. When the handle members 14', 17' are brought together asshown in FIG. 16, the arcuate finger member 65 is further distorted,thereby increasing the torque urging the clamp 10' toward its normallyclosed position.

Alternatively, as shown in FIGS. 17, 18, an arcuate finger member 66 maybe an extension from the clamping handle member 17"" which engages theinner surface of the base handle member 14", and exerts a torque urgingthe jaw members 13", 16" into proximity. When the handle members 17",14" are squeezed together as shown in FIG. 18, the arcuate finger memberis further distorted and exerts a greater torque.

The arcuate finger elements 65, 66 preferably are extruded when theresilient plastic elements (FIG. 5, FIG. 6) are extruded and are anintegral element of the extrusions 11', 12'.

The arcuate finger elements 65, 66 may be the sole resilient elementsurging the normally closed clamp into its normally closed condition.Alternatively, the arcuate finger elements 65, 66 may provide a torquein addition to that which is achieved from the cam member 15' (15") andthe cam engaging surface 19' (19").

Tendon Approximator

The present normally closed clamp, as shown in FIG. 19, may be providedwith one or more bores 67 which extend transversely through the clamp,preferably, through the base member 11.

As shown in FIG. 20, two or more of the present normally closed clamps10A, 10B are positioned parallel to each other and one or more rigidrods 68, 69 are press-fitted into the bores 67 of the clamps 10A, 10B tosupport the clamps 10A, 10B in a parallel relationship. The resultingassembly functions as a tendon approximator. As shown in FIG. 20, twoends of a tendon 70A, 70B are clamped in the clamps 10A, 10B,respectively. The clamps 10A, 10B are then drawn together by sliding oneor both of the clamps 10A, 10B along the rods 68, 69. With the abuttingends of the tendon 70A, 70B in confrontation, an operating surgeon cancarry out a tendon ligation procedure.

The clamps 10A, 10B may be made more effective for use in the tendonapproximator assembly as shown in FIG. 21. The jaw elements 16, 13 ofFIG. 8 are reproduced in FIG. 21 with a sharp spike element 71 extendingfrom an arcuate groove 26 of one jaw element 16 into the arcuate groove26 of the opposing jaw element 13. The sharp spike 71 penetrates thetendon 70A to improve the resistance to tendon pullout from the clamp10A.

Towel Clamp

A further embodiment of the present normally closed clamp isparticularly useful as a towel clamp. In many surgical procedures, theanatomy of a surgical patient which is not exposed during the surgicalprocedure is covered with drapes or towels, usually made from non-wovenfabric and intended to be discarded after a single use. In order tosecure the towels during the surgical procedure, the present practice isto use pointed clamps called towel clips which are customarilyfabricated from surgical steel and which are recovered after eachoperation for sterilization and reuse. The clamps are initiallyexpensive and they require costly sterilization between uses.

A normally closed clamp as illustrated in FIGS. 22, 23 permits single,throwaway use of an inexpensive normally closed clamp. As shown in FIGS.22, 23, the towel clamp embodiment 10A includes a base member 11A and aclamping member 12A. The base member 11A includes a handle member 14A, acam element 15A and a base jaw member 13A. The clamping member 12Aincludes a handle 17A, a clamping jaw member 16A, a central body member18A and a cam engaging surface 19A. The base jaw member 13A has aforward tip 31 and a concave surface 33 which confronts the clamping jawmember 16A. The clamping jaw member 16A has a forward tip 32 and aconcave surface 34 confronting the base jaw member 13A. The two concavesurfaces 33, 34 define an opening 35 between the jaw members 13A, 16A.

At least one of the tips 31, 32 is preferably sharpened to a beveled orpointed edge in order to provide a firm engagement with a clampedfabric. In the open position of the clamp 10A shown in FIG. 23, thehandle members 14A, 17A are brought together and the tips 31, 32separate to provide a throat for receiving within the opening 35 asubstance to be secured by the clamp, for example, the fabric formingsurgical drapes.

Tubing Clamp

A further embodiment of the present normally closed clamp isparticularly useful as a tubing clamp.

A normally closed clamp as illustrated in FIGS. 24, 25 provides softresilient liners. The clamp 10B includes a base member 11B and aclamping member 12B. The base member 11B includes a handle member 14B, acam element 15B and a base jaw member 13B. A clamping member 12Bincludes a handle 17B, a clamping jaw member 16B, a central body member18B and a cam engaging surface 19B. The base jaw member 13B has a pad 36which confronts the clamping jaw member 16B. The clamping jaw member 16Bhas a pad 37 confronting the base jaw member 13B. The two pads 36, 37are formed from a soft, resilient substance, such as a pliable plastic,preferably a foamed polymeric composition such as a foamed polyurethaneelastomer. The pads 36, 37 may be preformed and secured to the jawmembers 13B, 16B by adhesives or other fastening means. The pads 36, 37may be extruded integrally with the clamp members 11B, 12B respectivelyby well known dual durometer extrusive procedures.

The lined clamp of FIGS. 24, 25 is of particular value as a tubing clampto close fragile tubing without damage to the tubing walls.

FIG. 25 shows the clamp 10B in its open condition with the two pads 36,37 spaced-apart to receive an element (not shown) which is to beclamped.

We claim:
 1. A tendon approximator including two normally closed clamps,each clamp comprising two connected elements including:a base elementhaving a base jaw member, a base handle member and a central,non-circular arcuate cam member; a clamping element having a clampingjaw member, a clamping handle member and a non-circular arcuatecam-engaging member; said base element being secured to said clampingelement by engagement of at least a portion of said cam-engaging memberwith said cam member; said base jaw member and said clamping jaw memberhaving confronting surfaces which are in proximity when saidcam-engaging member conforms to the surface of said cam member;each saidclamp having two transverse bores; a pair of rods fitting incorresponding ones of said bores to support the said two clamps ingenerally parallel relation; at least one of said clamps being slideablealong the said rods with respect to the other of said clamps.
 2. Atendon approximator as defined in claim 1 wherein the said jaw membersof one clamp have corresponding transverse channels to receive a tendon.3. The tendon approximator of claim 2 wherein a sharp spike ispositioned in one of the said channels to penetrate and retain a tendonwithin the said one of said channels.